Stenus dashaheensis, Liu, Sheng-Nan, Tang, Liang & Luo, Yong-Ting, 2017

Liu, Sheng-Nan, Tang, Liang & Luo, Yong-Ting, 2017, Three new species of the Stenuscirrus group from Guizhou, southwest China (Coleoptera, Staphylinidae), ZooKeys 716, pp. 95-103 : 96-97

Stenus dashaheensis sp. n. Figs 1, 2, 7-12

Material examined.

CHINA: Guizhou: Holotype: ♂, glued on a card with labels as follows: "China: N. Guizhou, Daozhen Co., Dashahe, 29°10'12"N, 107°33'36"E, mixed leaf litter, sifted, 1730 m, 07.VII.2015, Jiang, Peng, Tu & Zhou leg.". "Holotype / Stenus dashaheensis / Liu, Tang & Luo" [red handwritten label] (SHNU). Paratypes: 2♂♂3♀♀, same data as for the holotype. (SHNU, cPut).

Diagnosis.

The new species can be distinguished from other related species by the following characters: body size smaller (BL <4.2 mm), elytra distinctly shorter than wide (EL/EW= 0.84-0.90), the rather smooth surfaces of pronotum and elytra, and the larger and less confluent punctation of pronotum and elytra than abdomen.

Description.

Brachypterous; body dark brown, each elytron with an orange spot near lateral margin. Antennae except the infuscate club, maxillary palpi, and legs yellowish brown. Labrum reddish brown. BL: 3.3-4.1 mm, FL: 1.7-2.0 mm. HW: 0.69-0.84 mm, PL: 0.55-0.65 mm, PW: 0.53-0.61 mm, EL: 0.57-0.68 mm, EW: 0.64-0.78 mm, SL: 0.43-0.49 mm.

Head 1.06-1.18 times as wide as elytra; interocular area with two deep longitudinal furrows, median portion convex, extending beneath the level of inner eye margins; punctures round, slightly larger and sparser on median portion than those near inner margins of eyes, diameter of large punctures slightly wider than apical cross section of antennal segment II; interstices between punctures smooth, much narrower than half the diameter of punctures except those along the midline of the median portion, which may be slightly narrower than the diameter of punctures. Paraglossae oval.

Pronotum 0.98-1.05 times as long as wide; disk relatively smooth (without impressions) with median longitudinal furrow indistinct; punctures round and slightly confluent, variable in size, slightly larger than those of head; interstices smooth, much narrower than half the diameter of punctures except for few near the actual middle, which may be as wide as the diameter of punctures.

Elytra 0.84-0.90 times as long as wide; disk relatively smooth; punctures round to elliptical, moderately confluent, similar in size to those on pronotum; interstices smooth, distinctly smaller than half the diameter of punctures.

Legs with tarsomeres IV strongly bilobed.

Abdomen cylindrical; paratergites very narrow and almost impunctate, present only in segment III, tergites and sternites totally fused in segments IV–VI, posterior margin of tergite VII with an indistinct apical membranous fringe; punctation of tergites III–VIII sparse and shallow, gradually becoming smaller posteriorly; interstices smooth, mostly wider than diameter of punctures except those on basal impressions of tergites III–V, which may be distinctly narrower than half the diameter of punctures.

Male. Sternite VIII (Fig. 7) with distinct triangular emargination at middle of posterior margin; sternite IX (Fig. 8) with long apicolateral projections, posterior margin serrated. Aedeagus (Figs 9-10) with apical sclerotized portion weakly prominent at apex; sclerotized expulsion clasps large, median ventral band long, narrow, dorsal bands short and relatively broad, lateral longitudinal bands short; copulatory tube stout; parameres longer than median lobe, each with 10-13 setae on apico-internal margins.

Female. Sternite VIII as in Fig. 11; sclerotized spermatheca (Fig. 12) consisting of basal duct, swollen spermathecal duct, and capsule.

Distribution.

China (Guizhou).

Remarks.

The new species is similar to S. bullatus Liu & Tang, 2017 from Guangxi, but can be easily distinguished from the latter by the less confluent punctation of the pronotum and the elytra, and by shorter elytra (in S. bullatus EL/EW = 0.90-1.07).

Etymology.

The specific name is derived from the type locality of this species.